Before training the network, we need to shuffle these images then load batch of images to feed the neural network. Before we describe how we solve it, let's do some calculation first: A very naive approach is loading from a list by random seeking. If use this approach, we will spend 677 hours with HDD or 6.7 hours with SSD respectively. This is only about read. Although SSD looks not bad, but 1TB SSD is not affordable for everyone.

ABS: We propose a systematic approach to reduce the memory consumption of deep neural network training. Specifically, we design an algorithm that costs O(sqrt(n)) memory to train a n layer network, with only the computational cost of an extra forward pass per mini-batch. As many of the state-of-the-art models hit the upper bound of the GPU memory, our algorithm allows deeper and more complex models to be explored, and helps advance the innovations in deep learning research. We focus on reducing the memory cost to store the intermediate feature maps and gradients during training. Computation graph analysis is used for automatic in-place operation and memory sharing optimizations.